Page 1 of 1

MPLS / VPLS - cant ping each other

Posted: Thu Nov 21, 2013 12:02 am
by lcm
Hi guys,

i need some help here, this is my scenario:

Rt1 -> Rt2 -> Rt3 -> Rt4 -> Rt5

Rt1
RouterOS 5.26
Rb1100AHx2

Rt2 to Rt5
RouterOS 5.26
Rb1200

They are running OSPF + MPLS with a /29 between each router.
vpls tunel with LDP

The problem:

I can estabilish the vpls and Ping from Rt1 to Rt2,3,4 the tunel with Rt1-Rt5 is estabilished but cant ping each other.

Ldp interfaces have been added, mpls interface MTU is 1500 for all.

some clues?

More info:
i did a sniffer and attached the image. it seens cant find the interface (unknown)

Re: MPLS / VPLS - cant ping each other

Posted: Mon Nov 25, 2013 8:18 pm
by lcm
anyone out there?

Re: MPLS / VPLS - cant ping each other

Posted: Mon Nov 25, 2013 11:19 pm
by CelticComms
It isn't clear which IPs you have assigned to the VPLS interfaces or what the routing table looks like on R1 & R5.

Re: MPLS / VPLS - cant ping each other

Posted: Mon Nov 25, 2013 11:37 pm
by lcm
ok, i'm sorry about that, i'll try to be clear:

vpls from Router 1 to Router2:
r1 vpls ip-192.168.0.1
r2 vpls ip-192.168.0.2
Status running.
ping OK


vpls from Router 1 to Router3:
r1 vpls ip-192.168.0.1
r3 vpls ip-192.168.0.2
Status running.
ping OK

vpls from Router 1 to Router4:
r1 vpls ip-192.168.0.1
r4 vpls ip-192.168.0.2
Status running.
ping OK

vpls from Router 1 to Router5:
r1 vpls ip-192.168.0.1
r5 vpls ip-192.168.0.2
Status running.
ping NOT OK


With default ping size.
i can ping from outside the vpls

Re: MPLS / VPLS - cant ping each other

Posted: Tue Nov 26, 2013 12:27 am
by CelticComms
Does it show running at both ends - R1 & R5? (I ask because it is possible to get one end showing running and the other end not...)

Any firewall differences on R5?

Re: MPLS / VPLS - cant ping each other

Posted: Tue Nov 26, 2013 9:00 am
by shahbazian
You say:
mpls interface MTU is 1500 for all.
But I thing you should use 1526 for mpls interface MTU when use vpls.
/mpls interface
set 0 interface=all mpls-mtu=1526

Re: MPLS / VPLS - cant ping each other

Posted: Tue Dec 10, 2013 4:59 pm
by lcm
Does it show running at both ends - R1 & R5? (I ask because it is possible to get one end showing running and the other end not...)

Any firewall differences on R5?
thanks for the answer.

yes, running on both ends.

no firewall at all.

Re: MPLS / VPLS - cant ping each other

Posted: Tue Dec 10, 2013 5:01 pm
by lcm
You say:
mpls interface MTU is 1500 for all.
But I thing you should use 1526 for mpls interface MTU when use vpls.
/mpls interface
set 0 interface=all mpls-mtu=1526

thanks for the answer.

yes i know i should, but i have some mtu problema with wireless devices. so if i keep the mtu 1500 the RB must fragment the packet, right?

Re: MPLS / VPLS - cant ping each other

Posted: Sat Mar 01, 2014 12:57 am
by shahbazian
so if i keep the mtu 1500 the RB must fragment the packet, right?
If MTU is too large and next header is IP
Then generate “ICMP Need Fragment error”
Else silently discard packet